Camilla is holding Bluebell, and Charles is holding Beth. Both dogs were rescued from Battersea Dogs and Cats home, which Camilla is a patron of.

The duchess has written of Beth and Bluebell in the past: “They are family, friends and ever-faithful companions and, just like anyone else with a passion for dogs, I can’t imagine life without them.”

The prince has a plaster on the end of one of his middle fingers, but Clarence House declined to comment as to why. The photo was taken by one of their staff members as they operate a reduced household.

Charles and Camilla visit the Tower of London. (Getty Images)

The prince and the duchess – formerly Camilla Parker Bowles – wed in a civil ceremony at the Windsor Guildhall on April 9 2005, after a relationship spanning more than 30 years.

Any celebrations will have to be low-key as they follow government guidelines on social distancing along with the rest of the Royal Family.

The couple has played a role in the response to the coronavirus pandemic, with Camilla calling an 85-year-old woman who has to self-isolate as she thanked NHS volunteers for signing up to help with essential services.

Charles and Camilla's love story goes back further than their 15 year marriage. (Getty Images)

And the prince opened the new field hospital, NHS Nightingale, in east London via videolink last week.